The Anti-Defamation League is offering a one-time class about the Holocaust to White House press secretary Sean Spicer following comments he made during a press briefing on how Adolf Hitler did not use chemical weapons against his own people.

"Unfortunately, when the first days of Passover ended and we turned to our phones and televisions yesterday evening, we learned about your comment that Hitler did not gas his own people. Your comparisons between [Syrian dictator Bashar] Assad and Hitler were not only historically inaccurate but they also were inappropriate and offensive," ADL CEO Jonathan A. Greenblatt said in a letter to Spicer.

"ADL would be happy to conduct one of these trainings at your convenience for you, your staff, and anyone at the White House who may need to learn more about the Holocaust," Greenblatt said. "We know you are very busy, but we believe a few hours learning this history will help you understand where you went wrong and prevent you from making these mistakes in the future."

The training includes historical context for how the Holocaust was able to occur, a human-interest look at the event and creates opportunities for critical thinking on the issue.

ADL has trained more than 130,000 law enforcement professionals and 35,000 educators on the Holocaust. In light of Spicer's "lack of knowledge" on the topic, the group hopes the White House communications official will take it up on the offer.

Spicer on Tuesday compared Assad to Hitler, saying that Hitler "didn't even sink to using chemical weapons" during World War II.

After a reporter pointed out the Holocaust, Spicer replied: "He brought them into the Holocaust centers, I understand that," Spicer said. "But in the way that Assad used them, where he went into towns and dropped them down to innocent in the middle of towns. I appreciate the clarification, that was not the intent."

Greenblatt also took a swipe at Spicer for a January incident in which the White House's International Holocaust Remembrance Day statement omitted Jews, calling Spicer's defense "vociferous."

ADL did not disclose the cost of the training or if it is complimentary.